根据短文选出正确答案。
Jack is a twenty-year-old young man.Two years ago, when he finished middle school, he found work in a shop.  He usually works until ten o’clock in the evening. He is very tired. He often has supper quickly , then he goes to bed and soon falls asleep.
One day, he met his friend Mary on his way home. Mary was his classmate. They were both happy. He asked the girl to his house, and she agreed happily. He bought some fruit and drinks for her. And they talked about their school, teachers, classmates and their future. They talked for a long time.
“Look at your watch, please,” said the girl, “What time is it now?”
“Sorry, something is wrong with my watch,” said Jack, “Where's yours?”
“I left it at home.”
Jack thought for a moment and found a way. He began to stamp his foot on the floor, “Bang! Bang! Bang!”
The sound woke his grandma up. The old woman shouted downstairs(在楼下), “It's twelve o'clock in the night. Why are you still jumping upstairs(在楼上)?”
⑴Jack was______________when he finished middle school.
A. sixteen            B. eighteen             C. twenty
⑵From the story, we can know Mary is Jack's _____.
A. classmate          B. colleague (同事)     C.uncle
⑶The word “stamp”in the story means _______ in Chinese.
A.盖印               B.跺                    C.贴邮票
⑷Jack stamped his foot on the floor in order to (为了) ______________.
A. make his grandma angry
B. let his grandma tell him the time
C. let his grandma buy him a watch
⑸Jack and Mary talked about ______________.
A. their school, teachers and classmates
B.their future
C.A and B